Automatic safety release for adjusting means for pulp refiners and the like



y 2 1961 R. B. HONEYMAN 2,985,388

AUTOMATIC SAFETY RELEASE FOR ADJUSTING MEANS FOR PULP REFINERS AND THELIKE Filed June 29, 1959 2 Sheets-Sheet l INVENTOR.

F[g J ROBERT B. HONEYMAN ATTORNEY y 61 R. B. HONEYMAN 2,985,388

AUTOMATIC SAFETY RELEASE FOR ADJUSTING MEANS FOR PULP REFINERS AND THELIKE Filed June 29, 1959 2 Sheets-Sheet 2 Fig: ,3-

INVENTOR. ROBERT B. HONEYMAN Fig 5 ATTORNEY AUTOMATIC SAFETY RELEASE FORADJUSTING NEANS FOR PULP REFINERS AND THE LIKE Robert Blakeley Honeyman,Portland, Oreg., assignor to Morden Machines Company, Portland, reg., acorporation of Oregon Filed June 29, 1959, Ser. No. 823,672

2 Claims. (Cl. 241-32) This invention relates in general to varioustypes of machines for the treating and refining of pulp material, and,more specifically, to machines in which the material receives itstreatment by being required to pass between op.- posed attritioningsurfaces of a rotating element and an opposing non-rotating element,often referred to as a shell or stator.

As is well-known, adjustment of the spacing between the opposedattritioning surfaces or working faces of the rotating and non-rotatingelements is essential from time to time, not only to compensate for wearon the working faces of the elements, but also to regulate and controlthe treatment given to a particularmaterial. Consequently such machinesare provided with means for adjusting the rotating element in an axialdirection with respect to the non-rotating element, as for exampleadjusting the frustoconical rotating plug in an axial direction in aJordan machine or the plates in a disc refining machine, or foradjusting the non-rotating shell or plate in an axial. direction withrespect to the rotating member.

However, it may happen than an operator, when making the adjustment ofthe position of one element axially with respect to the other, willcause the opposed working faces .to be brought too close together forthe desired or most efficient treatment of the particular materialpassing through the machine, or else it may happen that material ofheavier quality and consistency will beintroduced into the machinewithout proper adjustment being made in the spacing between the workingfaces of the two elements. In either case the material does not receivethe most satisfactory treatment desired while, at the same time, agreater load is imposed on the motor or driving means for the rotatingelement. -Also, when this occurs, the

'axial thrust on the axially adjustable element is increased as a resultof the increased pressure of the material as it passes between theopposed working faces. Occasionally it may happen that foreign objects,such as .tramp metal, may be included in the material being passedthrough the treating machine. Such foreign objects, in attempting toforce their way between the working faces, will damage the machineextensively unless the spacing between the working faces is instantlyincreased under the increased axial thrust. In the present inventionsuch increased axial thrust, due to any of these causes, upon reaching apredetermined limited amount, is utilized to produce an automaticpartial release for the position adjusting means.

The object of the invention accordingly is to provide automaticallyoperating release means in conjunction with the positioning means forthe adjustable element in the pulp treating machine, which will enablethe adjustable element automatically and instantly to be moved slightlyaway from the companion element, thus increasing the spacing between theopposed working faces of the elements, whenever the axial thrust on theadjustable element exceeds a desired predetermined amount.

A related object of the invention is to provide such an automaticrelease which can quickly and easily be ad- Patented May 23, 1961 justedso as to be pre-set for any desired maximum limit of axial thrust on theadjustable element.

Another object of the invention is to provide an automatic release to beused in conjunction with mechanical adjusting means, which will not atany time interfere with, or render inoperative, such mechanicaladjusting means.

A still further object is to provide an automatic, pressure-operated,safety release for the adjusting means on pulp refiners and the likewhich will be simple and practical in construction and which will notpresent any particular maintenance problem.

The manner in which these objects and incidental advantages are achievedwith the present invention will be readily understood from the followingbrief description and explanation with reference to the accompanyingdraw ings. I

In the drawings:

Fig. 1 is a fragmentary plan view of a pulp refining machine with partof the automatic safety release mounted thereon, with portions of themachine and safety release shown in section for clarity, and with theconnected automatically-actuated safety release control showndiagramatically in elevation and partly in section;

Fig. 2 is a fragmentary sectional elevation on line 2-2 of Fig. 1A drawnto a larger scale; and

Fig. 3 is an end elevation, partly in section, of the pulp refiningmachine of Fig. 1 taken on line 3-3 of Fig. 1.

The pulp refining machine shown in part by way of illustration in Fig. lis a machine of atype described in US. Patent No. 2,547,830, issuedunder date of April 3, 1951, to C. W. Morden and entitled Treating andRefining Mac hine for Pulp Materials; and this machine includes ahousing 10, a non-rotating frusto-conical shell -11 mounted in thehousing, and a frusto-conical roto'r (not shown) co-axial With the shelland rotating Within. the shell, the pulp being caused to pass betweenthe opposed attritioning surfaces of the shell and rotor. In order toprovide for adjustment of the spacing between the two attritioningelements the shell is adjustable in an axial direction. In thisparticular device the shell has a pair of diagonally opposite integralside arms 12 which carry a pair of guides 13 respectively, which guidesare slidable in semi-cylindrical guideways 14 provided in the interiorwall of the housing 10. A pair of positioning shafts 15, which areparallel to the axis of the shell and rotor, have their reduced innerends rigidly secured to the arms 12 and guides 13 by clamping nuts 15.The outer ends of these shafts are threaded and carry identicaladjusting nuts 16 (see also Fig. 2). The outer peripheries of theseadjusting nuts 16 are provided with gear teeth adapted for meshing witha pair of identical worms 17 secured on an adjusting shaft 18. A handwheel 19, secured on the shaft 18, enables the axial position of theshell to be manually adjusted. This means for adjusting the position ofthe shell in an axial direction with respect to the rotor, as thus fardescribed, is similar to that provided in the machine in the abovementioned patent. Obviously power driven means could be used in place ofthe manual means for rotating the shaft 18 and thus for operating theshell adjusting mechanism.

In the carrying out of the present invention a pair of specially shapedidentical housings 20 are provided for the outer end portions of the twopositioning shafts 15 respectively. The end of each housing 20 is formedinto a hydraulic cylinder 21 and is provided with a hollow hydraulicpiston 22. One side of the adjusting nut 16 bears againstthe adjacentend of the associated piston 22 through the intermediary of suitableball-bearings and race 23. The other side of the adjusting nut 16 isengaged by a Washer 24' against which a spring 24 bears, which spring isheld under compression between the adjusting nut 16 assasss and washerand the other end of the housing 20. Thus the springs 24 keep theadjusting nuts 16 in engagement with the respective pistons 22 at alltimes. The adjusting nuts and their pistons are allowed a slightmovement axially within their housings. A suitable key and keyway 25hold each hydraulic piston 22 against rotation while permitting slidingmovement of the piston in an axial direction.

The two hydraulic cylinders 21 are connected through a common pipe line26 with one side of a pressure cylinder 27 and thus with the chamber 29of the pressure cylinder 27 as shownin Fig. 1. A diaphragm 28 separatesthe cylinder 27 into the two chambers 29 and 3t) and seals the twochambers from each other while allowing opposite volumetric fluctuationin the two chambers. A branch pipe 26' connects the pipe 26 to anelectric pressure switch 31 of well-known type. The chamber 29, thepipes 26 and26' and the ends of the two hydraulic cylinders 21 arefilled with a suitable hydraulic liquid, such as oil, through an oilfill 32 having a shut-off valve.

The other chamber 3d of the cylinder 27 is connected to a pipe 34 whichin turn is connected to a suitable source (not shown) of other fluid(such as water or compressed air), through the intermediary of thecontrol valve 35. A relief valve 36, operated by a solenoid 37, and apressure gauge 38 are also connected with the pipe 34. The solenoid 37is connected to a source of electric energy by means of electricpressure switch 31.

The chamber 30 and pipe 34 are filled with fluid until a predeterminedpressure is indicated on the gauge 38. Then the valve 35 is shut off toseal the fluid in the chamber 30 and pipe 34. The device is now readyfor operation as follows (referring to Fig. l):

The adjustment of the spacing between the opposed attritioning surfacesof rotor and shell is first accomplished as usual by manual rotation ofthe hand wheel 19 (or other means may be used for rotating the shaft 18and thus adjusting the positioning shafts 15 and therewith adjusting theshell 11). Then the electric pressure switch 31 is set so as to operatethe solenoid 37 for the relief valve 36 whenever the pressure in thepipe line 26, and thus in the hydraulic cylinders 21 exceeds a desiredpredetermined amount, and thus whenever the pressure of thepulp betweenthe attritioning surfaces of the rotor and shell becomes such that theaxial thrust on the adjustable element or shell is greater than desiredunder the particular conditions of operation. Should the shell positioninadvertently be adjusted so that the opposed attritioning surfacesare-brought too close together, then, when the machine is operated,resulting excessive pressure of the material passing between the opposedattritioning surfaces will increase the thrust of the shafts 15 againsttheir pistons 22 and increase the pressure in the hydraulic cylinders21,

and thus allow the positioning shafts l and therewith the shell 11, tobe moved slightly (to the leftas viewed in Fig. 1), under the force ofthe excessive axial thrust, so as to increase slightly the spacingbetween the shell and rotor. When this occurs the reduced pressure inchamber 30will be apparent from the lowered position of the indicator ofgauge 38. a 7

To re-set the safety release the operator opensthe valve 35 temporarilyto enable additional fluid to be delivered into the pipe 34 and chamber30 so as to bring the pressure indicated by the gauge 33 again up to thedesired level. When subsequent manual adjusting of the position of theshell lowers the reading of pressure. gauge 38 the 42 valve 35 is againopened and the pressure restored to the desired level for the system.

In the example illustratedthe adjusting means and the safety release forthe same have been shown as being employed with an axially adjustableshell or non-rotating element which is adjustedaxially by the pair ofpositioning shafts 15 attached to the shell 11 at diametrically,opposite points. The two springs 24, hearing against the respectivenuts 16, cause uniform movement of the shafts (to the left asviewed inFig. 1) even though the increased axial thrust on the shellistransmitted mainly to one of the shafts. It is to be understood that theinvention also operates in exactly the same manner when the rotatingelement, instead of the non-rotating element, is made axiallyadjustableand thus when thenon-rotating element remains fixed. With somepulp treating and refining machines it has become common practice forthe rotor shaft to be mounted in a bearing housing, which bearinghousing in turn isadjustable along the common axis of the .two elements,thus'enabling the position of the rotor element to be adjusted axiallywith respect to the non-rotating and non-adjustable element. Insuchtcaser the present invention is employed in the same manner aspreviously described for providing the same automatic safetyrelease forthe similar mechanical means used for adjusting the axial position ofsuchbearing housing for the rotor shaft.

IWhei'e the bearing housing for the rotor shaft is adjustable axiallyonly one positioning shaft may be required for positioning the bearinghousing. Again in other machines more than two positioning shafts may beused, especially when a shell of considerable sizeis the adjustableelement, thepositioning shafts of course always being adjusted inunison.' Thus the invention may be employed in the same manner wherethere is only a single positioning shaft or where a plurality ofpositioning shafts areemployed.

I claim: 1., In a material treating machine of the character describedhaving ,a pair of axially aligned elements with .opposedworking facesand one of said elements being axially adjustable with respect to theother, an adjusting shaft connected tosaid adjustable element, athreaded porsettable pressure-operated switch in said closed hydrauliccircuit, a chamber connected to said closed hydraulic circuit,,adiaphragm forming one wall of said chamber, a second chamber on theother side of said diaphragm, a

closed fluid pressure circuit connected to said second chamber, a reliefvalve in said second mentioned circuit, electrical. means for operatingsaid relief valve, said electricalmeans actuated by saidpressure-operated switch,

whereby when the passage of material between said elements causes athrust onsaid axially adjustable element and therewith on said nut andsaid piston in excess of that for which said switch is set, theoperation of said relief valve and the resulting extension of saiddiaphragm will enableslight axial movement of said piston, nut andadjustable element to take place in response to and relief of theexcessive pressure.

2. -A'material treating machine including a rotating element, a coaxialnon-rotating element, said, elements having opposed working faces fortreating the material passing therebetween, means for adjusting saidnon-rotating elementraxiallywith respect to said rotating element, saidmeans comprising apluralityof positioning shafts connected with saidnon-rotating elementand extending parallel to the axis ,ofsaidnQH-lotating element, each of said shafts having an identicallythreaded portion, identical adjusting nuts on said threaded portions,worm gear means for rotating said nuts in unison, a hydraulic cylinderin axial alignment with each shaft, a piston in each cylinder, saidpistons bearing against said nuts respectively on the sides of said nutsremote from said non-rotating element, spring means bearing against theopposite side of each nut and holding the nut against its piston, aclosed hydraulic circuit connected to said cylinders normallymaintaining said pistons and therewith said nuts against axial movement,a pre-settable pressure-operated switch in said closed hydrauliccircuit, a chamber connected to said circuit, a diaphragm forming onewall of said cham her, a second chamber on the other side of saiddiaphragm, a closed fluid pressure circuit connected to said secondchamber, a relief valve in said second mentioned circuit, electricalmeans for operating said relief valve,

6 said electrical means actuated by said pressure-operated switch,whereby when the passage of material between said elements causes athrust on said non-rotating element and therewith on said nuts andpistons in excess of that for which said switch is set, the operation ofsaid relief valve and the resulting extension of said diaphragm willenable slight axial movement of said pistons, nuts and non-rotatingelement to take place in respo'nse to and relief of the excessivepressure.

References Cited in the file of this patent UNITED STATES PATENTS2,547,830 Morden Apr. 3, 1951 2,674,163 Prevost Apr. 6, 1954 2,743,874Asplund May 1, 1956 2,876,958 Edwards et al Mar. 10, 1959

